Toremifene: where do we stand?

Toremifene is a chlorinated triphenylethylene that is indicated for postmen opausal breast cancer. For advanced disease, toremifene has been found to b e as effective and at least as well tolerated as tamoxifen. The same appear s to apply for adjuvant setting. After a total cumulative clinical exposure to toremifene of approximately 140 000 patient-years, only 9 cases of endo metrial carcinoma have been reported. The annual hazard rate (per 1000 pati ent-years) of developing endometrial carcinoma in breast cancer patients on adjuvant toremifene is 1.14 (versus tamoxifen 2.0 and placebo 0.4). Althou gh toremifene (being a partial agonist) may unmask pre-existing endometrial tumours, there is no clinical data implying that it would per sc cause end ometrial carcinoma. (C) 2000 Elsevier Science Ltd. All rights reserved.